Flexures Keep This Printed Displacement Sensor In Line

May 18, 2024 by Dan Maloney 4 Comments

When the job at hand is measuring something with micron-range precision, thoughts generally turn to a tool with a Mitutoyo or Starrett nameplate. But with a clever design and a little electronics know-how, it turns out you can 3D print a displacement sensor for measuring in the micron range for only about $10.

While the tool that [BubsBuilds] came up with isn’t as compact as a dial indicator and probably won’t win any industrial design awards, that doesn’t detract from its usefulness. And unlike a dial indicator — at least the analog type — this sensor outputs an easily digitized signal. That comes courtesy of a simple opto-interrupter sensor, which measures the position of a fine blade within its field of view. The blade is attached to a flexure that constrains its movement to a single plane; the other end of the flexure has a steel ball acting as a stylus. In use, any displacement of the stylus results in more or less light being received by the phototransistor in the opto-interrupter; the greater the deflection, the less light and the lower the current through the transistor. In addition to the sensor itself, [Bub] printed a calibration jig that allows precision gauge blocks or simple feeler gauges to be inserted in front of the stylus. The voltage across the emitter resistor for these known displacements is then used to create a calibration curve.

[Bub] says he’s getting 5-micron repeatability with careful calibration and multiple measurements of each gauge block, which seems pretty impressive to us. If you don’t need the digital output, this compliant mechanism dial indicator might be helpful too. Continue reading “Flexures Keep This Printed Displacement Sensor In Line” →

Big Server Fan Becomes Fume Extractor

May 16, 2024 by Lewin Day 12 Comments

[Anthony Kouttron] wanted a fume extractor for his personal electronics lab, but he didn’t like the look of the cheap off-the-shelf units that he found. Ultimately, he figured it couldn’t be that hard to build own portable fume extractor instead.

The build is based around a mighty 110-watt centrifugal fan from an IBM server that’s rated at approximately 500 CFM. It’s a hefty unit, and it should be, given that it retails at over $200 on DigiKey. [Anthony] paired this fan with off-the-shelf HEPA and activated carbon filters. These are readily available from a variety of retailers. He didn’t want to DIY that part of the build, as the filter selection is critical to ensuring the unit actually captures the bad stuff in the air. He ended up building a custom power supply for the 12-volt fan, allowing it to run from common drill batteries for practicality’s sake.

Few of us have need for such a beefy fume extractor on the regular. Indeed, many hobbyists choose to ignore the risk from soldering or 3D printing fumes. Still, for those that want a beefy fume extractor they can build themselves, it might be worth looking over [Anthony]’s initial work.

We’ve seen some other great DIY fume extractors before, too. Even those that use drill batteries! If you’ve been cooking up your own solution, don’t hesitate to drop us a line!

Adaptive Chef’s Knife Provides Better Leverage

May 16, 2024 by Donald Papp 24 Comments

[Colleen] struggled with using a chef’s knife to cut a variety of foods while suffering from arthritis in her wrist and hand. There are knives aimed at people with special needs, but nothing suitable for serious work like [Colleen]’s professional duties in a commercial kitchen.

As a result, the IATP (Illinois Assistive Technology Program) created the Adaptive Chef’s Knife. Unlike existing offerings, it has a high-quality blade and is ergonomically designed so that the user can leverage their forearm while maintaining control.

The handle is durable, stands up to commercial kitchen use, and is molded to the same standards as off-the-shelf knife handles. That means it’s cast from FDA-approved materials and has a clean, non-porous surface. The pattern visible in the handle is a 3D printed “skeleton” over which resin is molded.

Interested? The IATP Maker Program makes assistive devices available to Illinois residents free of charge (though donations in suggested amounts are encouraged for those who can pay) but the plans and directions are freely available to anyone who wishes to roll their own.

Assistive technology doesn’t need to be over-engineered or frankly even maximally efficient in how it addresses a problem. Small changes can be all that’s needed to give people meaningful control over the things in their lives in a healthy way. Some great examples are are this magnetic spoon holder, or simple printed additions to IKEA furnishings.

Sandwizz Promises To Reinvent The Breadboard

May 13, 2024 by Tom Nardi 42 Comments

The solderless breadboard is perhaps the electronic hobbyist’s most commonly used tool, but let’s be honest, it isn’t exactly anyone’s favorite piece of gear. Even if you’ve got an infinite supply of jumpers in just the right size, any mildly complex circuit quickly becomes a nightmare to plan out and assemble. To say nothing of the annoyance of trying to track down an intermittent glitch, only to find you’ve got a loose wire someplace…

The Sandwizz Breadboard hopes to address those problems, and more, by turning the classic breadboard into a high-tech electronics prototyping platform. The Sandwizz not only includes an integrated power supply capable of providing between 1.8 and 5 volts DC, but also features an array of integrated digital and analog components. What’s more, the programmable connection system lets you virtually “wire” the internal and external components instead of wresting with jumper wires.

To configure the Sandwizz, you just need to connect to the device’s serial interface with your favorite terminal emulator and work your way through its text-based menus. You can also export a netlist file from your KiCad schematic and upload it into the board to make all the necessary connections automatically. This lets you make the leap from concept to physical prototype in literally seconds.

Continue reading “Sandwizz Promises To Reinvent The Breadboard” →

Pi with the PiFEX shield on the right, the SSD under test on the left with testpoints held by a jumper clip, jumper wires connecting the two together

JTAG Hacking An SSD With A Pi: A Primer

May 12, 2024 by Arya Voronova 4 Comments

[Matthew “wrongbaud” Alt] is well known around these parts for his hardware hacking and reverse-engineering lessons, and today he’s bringing us a JTAG hacking primer that demoes some cool new hardware — the PiFEX (Pi Interface Explorer). Ever wondered about those testpoint arrays on mSATA and M.2 SSDs? This write-up lays bare the secrets of such an SSD, using a Pi 4, PiFEX, OpenOCD and a good few open-source tools for JTAG probing that you can easily use yourself.

The PiFEX hat gives you level-shifted bidirectional GPIO connectors for UART, SPI, I2C, JTAG, SWD and potentially way more, an OLED screen to show any debugging information you might need, and even a logic analyzer header so that you can check up on your reverse-engineering progress.

Continue reading “JTAG Hacking An SSD With A Pi: A Primer” →

Tweeze Your Way To Soldering Success!

May 12, 2024 by Jenny List 25 Comments

Soldering, for those of us who spend a lot of time at an electronics bench, is just one of those skills we have, in the way that a blacksmith can weld or a tailor can cut clothing. We have an uncommon skill with hot metal and can manipulate the tiniest of parts, and incidentally our chopstick skills aren’t that bad as a consequence, either.

But even the best with a soldering iron can find useful tips from an expert, and that’s where [Mr SolderFix] comes in. His channel is chock-full of soldering advice, and in his latest video he takes a look at tweezers. They’re a part of the solderer’s standard kit and we all have several pairs, but it’s fair to say that we don’t always have the right pair to hand.

It was refreshing to hear him confirm that a good pair of tweezers, once a certain quality threshold has been met, need not necessarily be the most expensive set. We’ve certainly seen expensive tweezers with suspiciously bendy ends, and have found random AliExpress purchases which have stood the test of time. He also makes the point about which situations a set of tweezers with serrated heads might be more useful, and he demonstrates with a crystal oscillator.

As with photography though, we’d observe that sometimes the best set of tweezers to rectify a mishap are the ones in your hand. If you’re interested in more from [Mr SolderFix], we’ve featured his work more than once in the past. When he showed us how to lift SMD pins, for example.

A pile of red Swiss Army knives, probably collected by TSA.

Introducing The Swiss Army… Tool?

May 9, 2024 by Kristina Panos 152 Comments

You’ve probably used one for everything from opening packages to stripping wires in a pinch (because you know better than to use your teeth). We’re talking about the blade of the iconic Swiss Army knife. And while there are many different models out there, they all feature at least one knife among their utensils. Until now.

Citing pressure due to the increase in worldwide knife violence, the company announced that they’ll be releasing a new range of tools without blades. Carl Elsner, fourth-generation CEO of Swiss Army knife maker Victorinox, is also concerned about increasing regulations surrounding knives at sporting events and other activities. And he has a point: according to the UN’s Global Study on Homicide 2023 (PDF), 30% of European homicides were committed with some type of sharp object.

In an interview with The Guardian, Elsner spoke of creating more specialized tools, such as one for cyclists, who don’t necessarily need a blade. He also mentioned that Victorinox have a tool specifically for golfers, but we’d like to point out that it features, among other things, a knife.

It’s going to be a long time before people stop assuming that the skinny red thing in your pocket contains a knife, especially at the airport. What TSA agent is going to take the time to check out your tool? They’re going to chuck it in the bucket with the rest of them. Would you consider buying a blade-less multi-tool? Let us know in the comments.

Don’t have much need for a knife? Here’s a bench tool that has it all.

(Main and thumbnail photos via Unsplash)